The invention relates to a differential-brake group for vehicle driving axles.
Specifically, but not exclusively, the invention finds application in large vehicle axles. For such types of vehicles, the braking of the drive wheels is preferably made on the half-shafts that receive the drive from a differential and transmit it with or without a final velocity reduction, to the wheel hubs.
Commonly used are oil-immersed disk brakes which can conveniently use the mass of lubricant present in the axle for the dissipation of the considerable quantity of thermal energy created during the braking action.
The prior art embraces the use of disk brakes inserted as an integral part in the structure of the axle. In such cases, the axle is formed in more than one segment, usually three: two lateral segments which contain the half-shafts and one central segment which contains the differential group. The brakes are contained in autonomous segments which are mounted and solidly assembled between lateral segments and the central segment to form a single structure. In such conditions, obviously, the dismounting and the subsequent remounting of the brakes on the relative half-shafts necessarily brings about the mounting and the remounting of the axle in its segments. Remembering that the attachment points of the axle of the vehicle are situated at the lateral segments, the simple need to dismount the brakes for maintenance operations leads to the complete dismounting of the axle from the vehicle.
The prior art also embraces axles formed in a single piece exhibiting two lateral apertures, one for each side of the axle, predisposed in such a way that an entire brake assembly can be introduced and thus also extracted, which brake assembly comprises a frame internally to which a device for the execution of the braking is predisposed. The assembly is fixed to the axle by means of an external flange.
Such solutions, while solving the fundamental problem of permitting the realization of the axle in a single piece, and thus enormously facilitating all the mounting and dismounting operations of the brakes, require that the two openings at the sides of the central part of the axle must be specially designed and have a certain mass which, even if perfectly tolerable for large-sized vehicles, may be difficult to design for smaller vehicles.
Further, the making of the two apertures by the side of the central aperture, which serves to connect the differential to the drive transmission shaft, requires the performing of sufficiently accurate working for each aperture.